Fix == strict balance assertion parsing and correct README API examples

Message

split-balance-assertion was only skipping one character past the = sign, so == assertions left the second = in the amount string. Now detects == and skips both characters. Also fixes README to use actual API names (journal-transaction, not make-journal-transaction) and correct function signatures for the report module.

Added tests for == assertions, cost+assertion combos, and -$50/$-50 negative amount formats.

Changed

 README.md            | 21 ++++++++-------------
 src/sigil/ledger.sgl |  8 ++++++--
 test/test-ledger.sgl | 39 ++++++++++++++++++++++++++++++++++++++-
 3 files changed, 52 insertions(+), 16 deletions(-)

Diff

README.mdmodified

@@ -20,21 +20,19 @@ A Sigil library for reading, writing, and querying [hledger](https://hledger.org

(define txns (read-journal "/path/to/finances.journal"))

;; Create a new transaction

−23

(define txn (make-journal-transaction

+23

(define txn (journal-transaction

date: "2026-03-25"

status: "*"

description: "Coffee Shop"

postings: (list

−28

(make-journal-posting

+28

(journal-posting

account: "expenses:food:coffee"

−30

amount: (make-journal-amount quantity: 4.50 commodity: "EUR"))

−31

(make-journal-posting

+30

amount: (journal-amount quantity: 4.50 commodity: "EUR"))

+31

(journal-posting

account: "assets:wise:eur"))))

−34

;; Append to journal with dedup

−35

(append-transactions "/path/to/finances.journal"

−36

(list txn)

−37

dedup-tag: "ref")

+34

;; Append new transactions to journal

+35

(append-transactions "/path/to/finances.journal" (list txn))

```

### Reports via hledger CLI

@@ -43,13 +41,10 @@ A Sigil library for reading, writing, and querying [hledger](https://hledger.org

(import (sigil ledger report))

;; Run a balance report

−46

(define bal (hledger-balance journal: "/path/to/finances.journal"

−47

args: '("--tree" "assets")))

+44

(hledger-balance "/path/to/finances.journal" "assets" tree: #t)

;; Income statement for a period

−50

(define is (hledger-income-statement

−51

journal: "/path/to/finances.journal"

−52

args: '("--period" "2026-03")))

+47

(hledger-income-statement "/path/to/finances.journal" period: "2026-03")

```

## Journal Format Support

src/sigil/ledger.sglmodified

@@ -503,11 +503,15 @@

503

(amount (parse-amount-string amount-str)))

504

(list account amount cost assertion)))

505

−506

;; Split off balance assertion (= amount) from end

+506

;; Split off balance assertion (= or == amount) from end

507

(define (split-balance-assertion text)

508

(let ((eq-pos (find-assertion-equals text)))

509

(if eq-pos

−510

(let ((assertion-str (string-trim (substring text (+ eq-pos 1) (string-length text)))))

+510

;; Determine if this is == (strict) or = (normal) and skip accordingly

+511

(let* ((skip (if (and (< (+ eq-pos 1) (string-length text))

+512

(char=? (string-ref text (+ eq-pos 1)) #\=))

+513

2 1))

+514

(assertion-str (string-trim (substring text (+ eq-pos skip) (string-length text)))))

515

(cons (string-trim (substring text 0 eq-pos))

516

(parse-amount-string assertion-str)))

517

(cons text #f))))

test/test-ledger.sglmodified

@@ -248,6 +248,20 @@

248

(posting (car (journal-transaction-postings (car txns)))))

249

(assert-equal -500.0 (journal-amount-quantity (journal-posting-amount posting)))))

250

+251

(test "parse negative left-symbol -$50"

+252

(let* ((text "2026-03-15 * Test\n expenses:food -$50.00\n assets:checking\n")

+253

(txns (parse-journal text))

+254

(posting (car (journal-transaction-postings (car txns)))))

+255

(assert-equal -50.0 (journal-amount-quantity (journal-posting-amount posting)))

+256

(assert-equal "$" (journal-amount-commodity (journal-posting-amount posting)))))

+257

+258

(test "parse internal negative $-50"

+259

(let* ((text "2026-03-15 * Test\n expenses:food $-50.00\n assets:checking\n")

+260

(txns (parse-journal text))

+261

(posting (car (journal-transaction-postings (car txns)))))

+262

(assert-equal -50.0 (journal-amount-quantity (journal-posting-amount posting)))

+263

(assert-equal "$" (journal-amount-commodity (journal-posting-amount posting)))))

+264

265

(test "parse inferred amount posting"

266

(let* ((text "2026-03-15 * Test\n expenses:food $50.00\n assets:checking\n")

267

(txns (parse-journal text))

@@ -301,7 +315,30 @@

315

(bal (journal-posting-balance-assertion posting)))

316

(assert-true (journal-amount? bal))

317

(assert-equal 5000.0 (journal-amount-quantity bal))

−304

(assert-equal "$" (journal-amount-commodity bal)))))

+318

(assert-equal "$" (journal-amount-commodity bal))))

+319

+320

(test "parse strict balance assertion (==)"

+321

(let* ((text "2026-03-15 * Verify\n assets:checking $0 == $5000.00\n income:salary\n")

+322

(txns (parse-journal text))

+323

(posting (car (journal-transaction-postings (car txns))))

+324

(bal (journal-posting-balance-assertion posting)))

+325

(assert-true (journal-amount? bal))

+326

(assert-equal 5000.0 (journal-amount-quantity bal))

+327

(assert-equal "$" (journal-amount-commodity bal))))

+328

+329

(test "parse cost with balance assertion"

+330

(let* ((text "2026-03-15 * Test\n assets:wise:eur 100.00 EUR @ 1.08 USD = 200.00 EUR\n assets:wise:usd\n")

+331

(txns (parse-journal text))

+332

(posting (car (journal-transaction-postings (car txns))))

+333

(cost (journal-posting-cost posting))

+334

(bal (journal-posting-balance-assertion posting)))

+335

(assert-true (journal-cost? cost))

+336

(assert-equal 'per-unit (journal-cost-type cost))

+337

(assert-true (journal-amount? bal))

+338

(assert-equal "EUR" (journal-amount-commodity bal))

+339

;; Verify quantity parses correctly (use = for numeric comparison

+340

;; since exact/inexact integers may not be equal? to each other)

+341

(assert-true (= 200 (journal-amount-quantity bal))))))

342

343

;; ========== Round-trip Tests ==========

344